Tray seats are common in households, nurseries, day-care centers and eating establishments to elevate and restrain children during eating, coloring and other seated activities. Trays or other utilitarian flat surfaces are provided on such chairs in convenient positions for use by the seated occupant. Typically, the tray takes the form of an eating tray that together with the seat back and seat bottom of the chair completely surrounds and confines the child during eating, to keep the child seated and to prevent food from spilling. Frequently, chairs such as these are also fitted with safety belts.
Chairs used by children also take the form of play desks which have chairs attached centrally or peripherally to a work surface for similar accommodation of children. Tray seats also exist for the accommodation of adults, such as for use in hospitals and in facilities for the treatment of the handicapped. Also, various tray seats in the form of chairs with pull-up study surfaces are known for use by pupils in school classrooms and study halls. Another type of tray seat used by passengers in airplanes has a tray folded flat against the back of a seat for pull down by the passenger sitting in back of the seat. A variation of airplane passenger seat has a tray that folds out of one arm rest across the occupant's lap. A second variation has slots at the front of each armrest to receive a snapped-in tray.
Tray seats of the type to which the present invention relates tend to be bulky structures. The common household high chair, for example, has a broad base to prevent its toppling over and, though foldable to some extent, occupies considerable space even in its collapsed folded configuration. In nurseries, day-care centers and other multiple children settings, conventional free-standing high chairs are particularly difficult to manage because of their bulk. Furthermore, stacking many such chairs for storage in closets or against walls adjacent a child play area presents a safety hazard to children who may accidentally topple them. Leaving them unfolded near a play area also presents a hazard and, moreover, reduces the space available for playing.
A number of variations of portable high chairs exist that can be supported on tables or placed for support over chairs. Such devices tend, however, to be too flimsy for nursery or day-care settings and take too long to set up in multiple children situations.
Conventional tray seats usually present a tray to the user at a single elevation above the seat bottom. This is a problem especially in children's high chairs wherein the trays tend to be too high for the younger infants and too low for the older toddlers.